1. Field of the Invention
This device is an improved tracheostomy tube assembly for human use, structured for respirator and oxygen supply attachments to help support breathing. This tracheostomy tube assembly is designed to significantly extend the length of time between cleaning of the outer cannula of the tracheostomy tube, greatly reduce irritation of the stoma, and also improve speech during oxygen therapy.
2. Description of the Prior Art
Tracheostomy tubes have been in use for some time for providing ventilation directly to the patient's trachea through an opening, or stoma, in the patient's throat. Existing tracheostomy tubes are generally comprised of an outer curved cannula with a removable inner cannula. The outer cannula is designed to remain inserted within the stoma to keep it patent, and contains an exterior plate with which it can be affixed around the neck with a tether, to prevent the cannula from becoming dislodged. The distal end of some outer cannulas of the past art is also affixed with an inflatable balloon, or endotracheal cuff, for closing off the trachea for ventilation by a mechanical respirator. The inner cannula is removable and is primarily designed for easy connection to a respirator, and for easy cleaning of the lumen of the tracheostomy tube. Tracheostomy tubes are provided in both metal and plastic units. Plastic units can also be reuseable or disposable items, with disposable items being the most popular.
The medical conditions which require tracheostomies vary considerably in their etiology and their severity. In some of the more serious conditions, the patient may not be able to breath unaided, and is therefore dependant on an artificial mechanical respirator for survival. Sometimes the patient's condition improves, and he is gradually weaned from the respirator and basically retrained to breath on his own. Oxygen therapy is often also required during some or all phases of treatment. Sometimes the tracheostomy tube must remain in place for the rest of the patient's life, while other times the surgery is reversed closing the stoma, and the patient resumes normal breathing. Therefore, there may exist a wide variety of pulmonary conditions which tracheostomy tubes must accommodate.
Current existing tracheostomy tube assemblies have problems associated with long term maintenance. One major problem is the occurrence of frequent or chronic infections in and around the stoma and within the trachea. The relatively long length of the existing outer cannulas provides greater surface area to retain secretions and therefore, infectious organisms. Some of the measures used to treat or prevent infections includes suctioning, and frequent replacement or cleaning of parts to remove the build up of secretions, and occasionally the administration of antibiotics. The replacement or cleaning procedure includes frequent removal, sometimes daily, of the inner cannula, with the outer cannula being removed much less often, generally at six week intervals. This cleaning procedure, especially of the outer cannula, can be very uncomfortable to the patient especially if the stoma and adjacent area is infected or irritated. The more infections that occur or persist, the more often the tracheostomy tube will generally be cleaned, which in turn further irritates the already sensitive tissue. Although the endotracheal cuff on the outer cannula is deflated prior to removal, the folds of the cuff also cause a great deal of discomfort as it is withdrawn from an irritated stoma. When in use and inflated, the endotracheal cuff also exerts significant pressure against the interior wall of the trachea, which over an extended period of time, is not only uncomfortable for the patient, but serious damage, such as necrosis of the tracheal wall, can eventually result. Currently, intermittent deflation of a permanent cuff is required to prevent damage of the tracheal lining. Some tracheostomy tubes even have two inflatable cuffs or balloons, which allows alteration of the pressure points by inflating each balloon at separate times.
The operation and maintenance of the tracheostomy tube can become a painful and tiring experience for the patient. Since the stoma has a tendency to close rather quickly when not kept patent by the outer cannula, the patient can become anxious during the cleaning procedure, or replacement of a new cannula, for fear of not having an adequate airway when the cannula is removed. When the patient experiences prolonged or chronic infections, his overall prognosis can be adversely affected by the persistent debilitating strain it causes.
Another disadvantage of the existing tracheostomy tubes is the threat of air leakage between the inner cannula and outer cannula, and therefore a tight seal must be maintained between the two. Since ventilation of a patient with a respirator necessitates a closed pressurized system, air leakage must be prevented around the inflated cuff, at the external connecting attachments, and also between the two cannulas.
The extended curvature of existing cannulas is basically generic, and often does not conform well to individual patient anatomies, resulting in one or more portions of the tube rubbing on the tracheal wall.
Patients not totally dependant on a respirator, often use oxygen attachments for administering oxygen directly into the trachea via a transtracheal oxygen tube from a portable oxygen tank. Most of the current oxygen attachments however, have the disadvantage of impairing the speech of the patient. One of the more common oxygen attachments looks similar in appearance to an oxygen mask, and is referred to as a tracheotomy mask. The tracheotomy mask is designed to fit over the outer cannula, and is secured in place with a tie which attaches the device around the neck of the patient. A transtracheal oxygen tubing is connected on one end to the mask, and the other end is generally attached to a portable oxygen tank. The major disadvantage of the tracheotomy mask is that the seal between the mask and tracheostomy opening is not complete and oxygen can escape around the edges of the mask. This system also does not provide back pressure for air escaping through the outer cannula when the person tries to speak. The patient must therefore cover the outer opening or lumen, generally with a finger, in order to force enough air through the vocal cords to produce speech. This procedure is awkward and inconvenient for the patient, requiring him to close off the opening every time he wishes to speak. There is also an increased risk of introducing germs into the trachea when the patient uses his or her fingers to obstruct the cannula opening.
A past art patent search was conducted to examine devices similar to my invention. Of those examined, the following were considered most relevant:
The D. P. Shiley et al patent, U.S. Pat. No. 3,693,624, issued on Sept. 26, 1972, represents the basic structure common to existing tracheostomy tubes, and is herein included as being representative of that particular group. Shiley teaches a Tracheotomy Tube, where the endotracheal cuff is affixed to the outer cannula instead of the inner cannula. The long length of the outer cannula, with affixed endotracheal cuff, provides extra surface area for accumulating infectious microbes. The Shiley et al device is in common use today and generally requires replacement or cleaning of the outer cannula at regular frequent intervals, commonly six weeks. The tube with which the cuff is inflated is also positioned on the exterior of the outer cannula and can create irritation to the stoma, along with the deflated cuff, as the cannula is removed. There also must be a tight seal between the inner and outer cannulas since air leakage could result when the system is attached to a respirator.
The U.S. patent titled Fenestrated Tracheostomy Tube which was granted to R. F. Eisele, on Aug. 1, 1989, U.S. Pat. No. 4,852,565, incorporates air passages or fenestrations into the upper surface wall of the outer cannula for the purpose of weaning the patient from a respirator by providing breathing apertures when the inner cannula is removed and the patient is disconnected from the respirator. However, the previously mentioned disadvantages of the prior art are still present in this device.
Another disadvantage of the prior art is the possibility of the inflated cuff rupturing or leaking. Since the damaged cuffs must be replaced by removal of the outer cannula, this could be a serious situation when the patient is dependant on a respirator. Re-insertion of a new outer cannula can be a difficult procedure, often requiring a doctor, and in some hospitals, doctors are mandated to perform the procedure.
Therefore, all of the previously mentioned disadvantages of the past art, especially the susceptibility for creating infections although indirectly, contribute to the patient's slow recovery. In some cases the infection can even prove fatal. Therefore any modification in existing tracheostomy equipment that significantly reduces the chance of infection and reduces discomfort to the patient is considered to be an advantage.
My invention significantly decreases the occurrence of infections, reduces the recovery time when weaning a patient from a respirator, and increases the patient's comfort.